Field of the Invention
The present invention relates to a hologram display apparatus and a method for controlling the same. More particularly, the invention relates to a hologram display apparatus having improved reliability by minimizing a deviation between luminance recognized by the left eye and luminance recognized by the right eye, and a method for controlling the same.
Discussion of the Related Art
There has been an increased interest in three-dimensional image display technology. One of the representative methods for displaying a three-dimensional image is a stereoscopic method. The stereoscopic method uses a disparity image between the left and right eyes to apply 3-D effects. Such a binocular disparity image can be generated using glasses.
The biggest problem of the stereoscopic method is that it is necessary for the user to wear glasses. Therefore, an autostereoscopic method which does not require wearing glasses has been developed. A hologram display technology has been studied as technology for displaying a three-dimensional image without using glasses.
According to the hologram display technology, an interference signal obtained by overlapping light reflected from an object with a coherent light is recorded, and stored and a hologram is displayed using the interference signal. A hologram display apparatus stores an interference pattern formed by using the interference signal and restores the interference signal by irradiating a reference light to the stored interference pattern, so that a three-dimensional hologram is displayed.
In the hologram display technology, an interference pattern may be generated by a computer. A hologram can be displayed by displaying an interference pattern on a liquid crystal spatial light modulator and irradiating a reference light to the liquid crystal spatial light modulator.
However, a spatial light modulator using a liquid crystal has too large a gap between pixels and thus has a very small angle of diffraction. Therefore, a problem of the spatial light modulator using a liquid crystal is a very narrow viewing window that may prevent the recognition of a hologram.